When we look at a modern map of Africa, we look long and need a magnifying glass before we can find Cape Bojador (Portuguese for “Bulging Cape”), on the west coast, just south of the Canary Islands. Some thousand miles north of the continent’s greatest westward bulge we see a tiny bump on the coastal outline, a “bulge” so slight that it is almost imperceptible on maps of the full continent. The sandy barrier there is so low that it can be seen only when one comes close, where was no worse than a score of other barriers that skillful Portuguese sailors had passed and survived. But this particular Cape Bojador they had made their ne plus ultra. You dare not go beyond!

When we see the enormous risky promontories, the Cape of Good Hope or Cape Horn, that European seafarers would manage to round within the next century, we must recognize Bojador as something quite else. It was a barrier in the mind, the very prototype of primitive obstacles to the explorer. […]

“The Portuguese Discoverers”, from “The Discoverers”, Daniel J. Boorstin, The National Board for the Celebration of Portuguese Discoveries, Lisbon, 1987